Polymeric material for an insulated container

ABSTRACT

A formulation includes a polymeric material, a nucleating agent, a blowing, and a surface active agent. The formulation can be used to form a container.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.14/739,510, filed Jun. 15, 2015, which is a continuation of U.S.application Ser. No. 14/486,618, filed Sep. 15, 2014, which is acontinuation of U.S. application Ser. No. 13/491,327, filed Jun. 7,2012, which claims priority under 35 U.S.C. §119(e) to U.S. ProvisionalApplications No. 61/529,632, filed Aug. 31, 2011 and No. 61/618,604,filed Mar. 30, 2012, each of which is expressly incorporated byreference herein.

BACKGROUND

The present disclosure relates to polymeric materials that can be formedto produce a container, and in particular, polymeric materials thatinsulate. More particularly, the present disclosure relates topolymer-based formulations that can be formed to produce an insulatednon-aromatic polymeric material.

SUMMARY

A polymeric material in accordance with the present disclosure includesa polymeric resin and cell-forming agents. In illustrative embodiments,a blend of polymeric resins and cell-forming agents is extruded orotherwise formed to produce an insulated cellular non-aromatic polymericmaterial.

In illustrative embodiments, an insulative cellular non-aromaticpolymeric material produced in accordance with the present disclosurecan be formed to produce an insulative cup or other product.Polypropylene resin is used to form the insulative cellular non-aromaticpolymeric material in illustrative embodiments.

In illustrative embodiments, an insulative cellular non-aromaticpolymeric material comprises a polypropylene base resin having a highmelt strength, a polypropylene copolymer or homopolymer (or both), andcell-forming agents including at least one nucleating agent and ablowing agent such as carbon dioxide. In illustrative embodiments, theinsulative cellular non-aromatic polymeric material further comprises aslip agent. The polypropylene base resin has a broadly distributedunimodal (not bimodal) molecular weight distribution.

In illustrative embodiments, a polypropylene-based formulation inaccordance with the present disclosure is heated and extruded in twostages to produce a tubular extrudate (in an extrusion process) that canbe sliced to provide a strip of insulative cellular non-aromaticpolymeric material. A blowing agent in the form of an inert gas isintroduced into a molten resin in the first extrusion stage inillustrative embodiments.

In illustrative embodiments, an insulative cup is formed using the stripof insulative cellular non-aromatic polymeric material. The insulativecup includes a body having a sleeve-shaped side wall and a floor coupledto the body to cooperate with the side wall to form an interior regionfor storing food, liquid, or any suitable product. The body alsoincludes a rolled brim coupled to an upper end of the side wall and afloor mount coupled to a lower end of the side wall and to the floor.

The insulative cellular non-aromatic polymeric material is configured inaccordance with the present disclosure to provide means for enablinglocalized plastic deformation in at least one selected region of thebody (e.g., the side wall, the rolled brim, the floor mount, and afloor-retaining flange included in the floor mount) to provide (1) aplastically deformed first material segment having a first density in afirst portion of the selected region of the body and (2) a secondmaterial segment having a relatively lower second density in an adjacentsecond portion of the selected region of the body. In illustrativeembodiments, the first material segment is thinner than the secondmaterial segment.

Additional features of the present disclosure will become apparent tothose skilled in the art upon consideration of illustrative embodimentsexemplifying the best mode of carrying out the disclosure as presentlyperceived.

BRIEF DESCRIPTIONS OF THE DRAWINGS

The detailed description particularly refers to the accompanying figuresin which:

FIG. 1 is a diagrammatic and perspective view of a material-formingprocess in accordance with the present disclosure showing that thematerial-forming process includes, from left to right, a formulation ofinsulative cellular non-aromatic polymeric material being placed into ahopper that is fed into a first extrusion zone of a first extruder whereheat and pressure are applied to form molten resin and showing that ablowing agent is injected into the molten resin to form an extrusionresin mixture that is fed into a second extrusion zone of a secondextruder where the extrusion resin mixture exits and expands to form anextrudate which is slit to form a strip of insulative cellularnon-aromatic polymeric material;

FIG. 2 is a perspective view of an insulative cup made from a strip ofmaterial including the insulative cellular non-aromatic polymericmaterial of FIG. 1 showing that the insulative cup includes a body and afloor and showing that four regions of the body have been broken away toreveal localized areas of plastic deformation that provide for increaseddensity in those areas while maintaining a predetermined insulativecharacteristic in the body;

FIG. 3 is an enlarged sectional view of a portion of a side wallincluded in the body of the insulative cup of FIG. 2 showing that theside wall is made from a sheet that includes, from left to right, a skinincluding a film, an ink layer, and an adhesive layer, and the strip ofinsulative cellular non-aromatic polymeric material of FIG. 1;

FIG. 4 is an exploded assembly view of the insulative cup of FIG. 2showing that the insulative cup includes, from top to bottom, the floorand the body including a rolled brim, the side wall, and a floor mountconfigured to interconnect the floor and the side wall as shown in FIG.2;

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2 showing thatthe side wall included in the body of the insulative cup includes agenerally uniform thickness and that the floor is coupled to the floormount included in the body;

FIGS. 6-9 are a series views showing first, second, third, and fourthregions of the insulative cup of FIG. 2 that each include localizedplastic deformation;

FIG. 6 is a partial section view taken along line 5-5 of FIG. 2 showingthe first region is in the side wall of the body;

FIG. 7 is a partial section view taken along line 5-5 of FIG. 2 showingthe second region is in the rolled brim of the body;

FIG. 8 is a partial section view taken along line 5-5 of FIG. 2 showingthe third region is in a connecting web included in the floor mount ofthe body;

FIG. 9 is a partial section view taken along line 5-5 of FIG. 2 showingthe fourth region is in a web-support ring included in the floor mountof the body; and

FIG. 10 is a graph showing performance over time of insulative cups inaccordance with the present disclosure undergoing temperature testing.

DETAILED DESCRIPTION

An insulative cellular non-aromatic polymeric material produced inaccordance with the present disclosure can be formed to produce aninsulative cup 10 as suggested in FIGS. 2-9. As an example, theinsulative cellular non-aromatic polymeric material comprises apolypropylene base resin having a high melt strength, a polypropylenecopolymer or homopolymer (or both), and cell-forming agents including atleast one nucleating agent and a blowing agent such as carbon dioxide.As a further example, the insulative cellular non-aromatic polymericmaterial further comprises a slip agent. The polypropylene base resinhas a broadly distributed unimodal (not bimodal) molecular weightdistribution.

A material-forming process 100 uses a polypropylene-based formulation121 in accordance with the present disclosure to produce a strip 82 ofinsulative cellular non-aromatic polymeric material as shown in FIG. 1.Formulation 121 is heated and extruded in two stages to produce atubular extrudate 124 that can be slit to provide strip 82 of insulativecellular non-aromatic polymeric material as illustrated, for example, inFIG. 1. A blowing agent in the form of a liquified inert gas isintroduced into a molten resin 122 in the first extrusion zone.

Insulative cellular non-aromatic polymeric material is used to forminsulative cup 10. Insulative cup 10 includes a body 11 having asleeve-shaped side wall 18 and a floor 20 as shown in FIGS. 2 and 4.Floor 20 is coupled to body 11 and cooperates with side wall 18 to forman interior region 14 therebetween for storing food, liquid, or anysuitable product. Body 11 also includes a rolled brim 16 coupled to anupper end of side wall 18 and a floor mount 17 coupled to a lower end ofside wall 18 and to floor 20 as shown in FIG. 5.

Insulative cellular non-aromatic polymeric material is configured inaccordance with the present disclosure to provide means for enablinglocalized plastic deformation in at least one selected region of body 11(e.g., side wall 18, rolled brim 16, floor mount 17, and afloor-retaining flange 26 included in floor mount 17) to provide (1) aplastically deformed first material segment having a first density in afirst portion of the selected region of body 11 and (2) a secondmaterial segment having a relatively lower second density in an adjacentsecond portion of the selected region of body 11 as suggested, forexample, in FIGS. 2 and 6-9. In illustrative embodiments, the firstmaterial segment is thinner than the second material segment.

One aspect of the present disclosure provides a formulation formanufacturing an insulative cellular non-aromatic polymeric material. Asreferred to herein, an insulative cellular non-aromatic polymericmaterial refers to an extruded structure having cells formed therein andhas desirable insulative properties at given thicknesses. Another aspectof the present disclosure provides a resin material for manufacturing anextruded structure of insulative cellular non-aromatic polymericmaterial. Still another aspect of the present disclosure provides anextrudate comprising an insulative cellular non-aromatic polymericmaterial. Yet another aspect of the present disclosure provides astructure of material formed from an insulative cellular non-aromaticpolymeric material. A further aspect of the present disclosure providesa container formed from an insulative cellular non-aromatic polymericmaterial.

In exemplary embodiments, a formulation includes at least one polymericmaterial. In one exemplary embodiment a primary or base polymercomprises a high melt strength polypropylene that has long chainbranching. Long chain branching occurs by the replacement of asubstituent, e.g., a hydrogen atom, on a monomer subunit, by anothercovalently bonded chain of that polymer, or, in the case of a graftcopolymer, by a chain of another type. For example, chain transferreactions during polymerization could cause branching of the polymer.Long chain branching is branching with side polymer chain lengths longerthan the average critical entanglement distance of a linear polymerchain. Long chain branching is generally understood to include polymerchains with at least 20 carbon atoms depending on specific monomerstructure used for polymerization. Another example of branching is bycrosslinking of the polymer after polymerization is complete. Some longchain branch polymers are formed without crosslinking. Polymer chainbranching can have a significant impact on material properties. Finalselection of a polypropylene material may take into account theproperties of the end material, the additional materials needed duringformulation, as well as the conditions during the extrusion process. Inexemplary embodiments high melt strength polypropylenes may be materialsthat can hold a gas (as discussed hereinbelow), produce desirable cellsize, have desirable surface smoothness, and have an acceptable odorlevel (if any).

One illustrative example of a suitable polypropylene base resin isDAPLOY™ WB 140 homopolymer (available from Borealis A/S), a high meltstrength structural isomeric modified polypropylene homopolymer (meltstrength=36, as tested per ISO 16790 which is incorporated by referenceherein, melting temperature=325.4° F. (163° C.) using ISO 11357, whichis incorporated by reference herein).

Borealis DAPLOY™ WB 140 properties (as described in a Borealis productbrochure):

Property Typical Value Unit Test Method Melt Flow Rate (230/2.16) 2.1g/10 min ISO 1133 Flexural Modulus 1900 MPa ISO 178 Tensile Strength atYield 40 MPa ISO 527-2 Elongation at Yield 6 % ISO 527-2 Tensile Modulus2000 MPa ISO 527-2 Charpy impact strength, 3.0 kJ/m² ISO 179/1eA notched(+23° C.) Charpy impact strength, 1.0 kJ/m² ISO 179/1eA notched (−20°C.) Heat Deflection Temperature 60 ° C. ISO 75-2 A (at 1.8 MPa load)Method A Heat Deflection Temperature 110 ° C. ISO 75-2 B (at 0.46 MPaload) Method B

Other polypropylene polymers having suitable melt strength, branching,and melting temperature may also be used. Several base resins may beused and mixed together.

In certain exemplary embodiments, a secondary polymer may be used withthe base polymer. The secondary polymer may be, for example, a polymerwith sufficient crystallinity. In exemplary embodiments the secondarypolymer may be at least one crystalline polypropylene homopolymer, animpact copolymer, mixtures thereof or the like. One illustrative exampleis a high crystalline polypropylene homopolymer, available as F020HCfrom Braskem. Another illustrative example is a polymer commerciallyavailable as PRO-FAX SC204™ (available from LyndellBasell IndustriesHoldings, B.V.). Another illustrative example is Homo PP—INSPIRE 222,available from Braskem. In one aspect the polypropylene may have a highdegree of crystallinity, i.e., the content of the crystalline phaseexceeds 51% (as tested using differential scanning calorimetry) at 10°C./min cooling rate. In exemplary embodiments several differentsecondary polymers may be used and mixed together.

In exemplary embodiments, the secondary polymer may be or may includepolyethylene. In exemplary embodiments, the secondary polymer mayinclude low density polyethylene, linear low density polyethylene, highdensity polyethylene, ethylene-vinyl acetate copolymers,ethylene-ethylacrylate copolymers, ethylene-acrylic acid copolymers,mixtures of at least two of the foregoing and the like. The use ofnon-polypropylene materials may affect recyclability, insulation,microwavability, impact resistance, or other properties, as discussedfurther hereinbelow.

One or more nucleating agents are used to provide and control nucleationsites to promote formation of cells, bubbles, or voids in the moltenresin during the extrusion process. Nucleating agent means a chemical orphysical material that provides sites for cells to form in a moltenresin mixture. Nucleating agents may be physical agents or chemicalagents. Suitable physical nucleating agents have desirable particlesize, aspect ratio, and top-cut properties. Examples include, but arenot limited to, talc, CaCO₃, mica, and mixtures of at least two of theforegoing. The nucleating agent may be blended with the polymer resinformulation that is introduced into the hopper. Alternatively, thenucleating agent may be added to the molten resin mixture in theextruder. When the chemical reaction temperature is reached thenucleating agent acts to enable formation of bubbles that create cellsin the molten resin. An illustrative example of a chemical blowing agentis citric acid or a citric acid-based material. After decomposition, thechemical blowing agent forms small gas cells which further serve asnucleation sites for larger cell growth from a physical or other typesof blowing agents. One representative example is Hydrocerol™ CF-40E™(available from Clariant Corporation), which contains citric acid and acrystal nucleating agent. In illustrative embodiments one or morecatalysts or other reactants may be added to accelerate or facilitatethe formation of cells.

In certain exemplary embodiments, one or more blowing agents may beincorporated. Blowing agent means a physical or a chemical material (orcombination of materials) that acts to expand nucleation sites.Nucleating agents and blowing agents may work together. The blowingagent acts to reduce density by forming cells in the molten resin. Theblowing agent may be added to the molten resin mixture in the extruder.Representative examples of physical blowing agents include, but are notlimited to, carbon dioxide, nitrogen, helium, argon, air, pentane,butane, or other alkane mixtures of the foregoing and the like. Incertain exemplary embodiments, a processing aid may be employed thatenhances the solubility of the physical blowing agent. Alternatively,the physical blowing agent may be a hydrofluorocarbon, such as1,1,1,2-tetrafluoroethane, also known as R134a, or other haloalkanerefrigerant. Selection of the blowing agent may be made to takeenvironmental impact into consideration.

In exemplary embodiments, physical blowing agents are typically gasesthat are introduced as liquids under pressure into the molten resin viaa port in the extruder as suggested in FIG. 1. As the molten resinpasses through the extruder and the die head, the pressure drops causingthe physical blowing agent to change phase from a liquid to a gas,thereby creating cells in the extruded resin. Excess gas blows off afterextrusion with the remaining gas being trapped in the cells in theextrudate.

Chemical blowing agents are materials that degrade or react to produce agas. Chemical blowing agents may be endothermic or exothermic. Chemicalblowing agents typically degrade at a certain temperature to decomposeand release gas. In one aspect the chemical blowing agent may be one ormore materials selected from the group consisting of azodicarbonamide;azodiisobutyro-nitrile; benzenesulfonhydrazide; 4,4-oxybenzenesulfonylsemicarbazide; p-toluene sulfonyl semi-carbazide; bariumazodicarboxylate; N,N′-dimethyl-N,N′-dinitrosoterephthalamide;trihydrazino triazine; methane; ethane; propane; n-butane; isobutane;n-pentane; isopentane; neopentane; methyl fluoride; perfluoromethane;ethyl fluoride; 1,1-difluoroethane; 1,1,1-trifluoroethane;1,1,1,2-tetrafluoro-ethane; pentafluoroethane; perfluoroethane;2,2-difluoropropane; 1,1,1-trifluoropropane; perfluoropropane;perfluorobutane; perfluorocyclobutane; methyl chloride; methylenechloride; ethyl chloride; 1,1,1-trichloroethane;1,1-dichloro-1-fluoroethane; 1-chloro-1,1-difluoroethane;1,1-dichloro-2,2,2-trifluoroethane; 1-chloro-1,2,2,2-tetrafluoroethane;trichloromonofluoromethane; dichlorodifluoromethane;trichlorotrifluoroethane; dichlorotetrafluoroethane;chloroheptafluoropropane; dichlorohexafluoropropane; methanol; ethanol;n-propanol; isopropanol; sodium bicarbonate; sodium carbonate; ammoniumbicarbonate; ammonium carbonate; ammonium nitrite;N,N′-dimethyl-N,N′-dinitrosoterephthalamide;N,N′-dinitrosopentamethylene tetramine; azobisisobutylonitrile;azocyclohexylnitrile; azodiaminobenzene; benzene sulfonyl hydrazide;toluene sulfonyl hydrazide; p,p′-oxybis(benzene sulfonyl hydrazide);diphenyl sulfone-3,3′-disulfonyl hydrazide; calcium azide; 4,4′-diphenyldisulfonyl azide; and p-toluene sulfonyl azide.

In one aspect of the present disclosure, where a chemical blowing agentis used, the chemical blowing agent may be introduced into the resinformulation that is added to the hopper.

In one aspect of the present disclosure, the blowing agent may be adecomposable material that forms a gas upon decomposition. Arepresentative example of such a material is citric acid or acitric-acid based material. In one exemplary aspect of the presentdisclosure it may be possible to use a mixture of physical and chemicalblowing agents.

In one aspect of the present disclosure, at least one slip agent may beincorporated into the resin mixture to aid in increasing productionrates. Slip agent (also known as a process aid) is a term used todescribe a general class of materials which are added to a resin mixtureand provide surface lubrication to the polymer during and afterconversion. Slip agents may also reduce or eliminate die drool.Representative examples of slip agent materials include amides of fatsor fatty acids, such as, but not limited to, erucamide and oleamide. Inone exemplary aspect, amides from oleyl (single unsaturated C-18)through erucyl (C-22 single unsaturated) may be used. Otherrepresentative examples of slip agent materials include low molecularweight amides and fluoroelastomers. Combinations of two or more slipagents can be used. Slip agents may be provided in a master batch pelletform and blended with the resin formulation.

One or more additional components and additives optionally may beincorporated, such as, but not limited to, impact modifiers, colorants(such as, but not limited to, titanium dioxide), and compound regrind.

The polymer resins may be blended with any additional desired componentsand melted to form a resin formulation mixture.

In addition to surface topography and morphology, another factor thatwas found to be beneficial to obtain a high quality insulative cup freeof creases was the anisotropy of the insulative cellular non-aromaticpolymeric strip. Aspect ratio is the ratio of the major axis to theminor axis of the cell. As confirmed by microscopy, in one exemplaryembodiment the average cell dimensions in a machine direction 67(machine or along the web direction) of an extruded strip 82 ofinsulative cellular non-aromatic polymeric material was about 0.0362inches (0.92 mm) in width by about 0.0106 inches (0.27 mm) in height. Asa result, a machine direction cell size aspect ratio is about 3.5. Theaverage cell dimensions in a cross direction (cross-web or transversedirection) was about 0.0205 inches (0.52 mm) in width and about 0.0106inches (0.27 mm) in height. As a result, a cross-direction aspect ratiois 1.94. In one exemplary embodiment, it was found that for the strip towithstand compressive force during cup forming, one desirable averageaspect ratio of the cells was between about 1.0 and about 3.0. In oneexemplary embodiment one desirable average aspect ratio of the cells wasbetween about 1.0 and about 2.0.

The ratio of machine direction to cross direction cell length is used asa measure of anisotropy of the extruded strip. In exemplary embodiments,a strip of insulative cellular non-aromatic polymeric material may bebi-axially oriented, with a coefficient of anisotropy ranging betweenabout 1.5 and about 3. In one exemplary embodiment, the coefficient ofanisotropy was about 1.8.

If the circumference of the cup is aligned with machine direction 67 ofextruded strip 82 with a cell aspect ratio exceeding about 3.0, deepcreases with depth exceeding about 200 microns are typically formed oninside surface of the cup making it unusable. Unexpectedly, it wasfound, in one exemplary embodiment, that if the circumference of the cupwas aligned in the cross direction of extruded strip 82, which can becharacterized by cell aspect ratio below about 2.0, no deep creases wereformed inside of the cup, indicating that the cross direction ofextruded strip 82 was more resistant to compression forces during cupformation.

One possible reason for greater compressibility of an extruded stripwith cells having aspect ratio below about 2.0 in the direction of cupcircumference, such as in the cross direction, could be due to lowerstress concentration for cells with a larger radius. Another possiblereason may be that the higher aspect ratio of cells might mean a higherslenderness ratio of the cell wall, which is inversely proportional tobuckling strength. Folding of the strip into wrinkles in the compressionmode could be approximated as buckling of cell walls. For cell wallswith longer length, the slenderness ratio (length to diameter) may behigher. Yet another possible factor in relieving compression stressmight be a more favorable polymer chain packing in cell walls in thecross direction allowing polymer chain re-arrangements under compressionforce. Polymer chains are expected to be preferably oriented and moretightly packed in machine direction 67.

In exemplary embodiments, the combination of alignment of the formed cupcircumference along the direction of the extruded strip where cellaspect ratio is below about 2.0. As a result, the surface of extrudedstrip with crystal domain size below about 100 angstroms facing insidethe cup may provide favorable results of achieving a desirable surfacetopography with imperfections less than about 5 microns deep.

In one aspect of the present disclosure, the polypropylene resin (eitherthe base or the combined base and secondary resin) may have a density ina range of about 0.01 g/cm³ to about 0.19 g/cm³. In one exemplaryembodiment, the density may be in a range of about 0.05 g/cm³ to about0.19 g/cm³. In one exemplary embodiment, the density may be in a rangeof about 0.1 g/cm³ to about 0.185 g/cm³.

In an alternative exemplary embodiment, instead of polypropylene as theprimary polymer, a polylactic acid material may be used, such as, butnot limited to, a polyactic acid material derived from a food-basedmaterial, for example, corn starch. In one exemplary embodiment,polyethylene may be used as the primary polymer.

In one exemplary aspect of the present disclosure, one formulation for amaterial useful in the formation of an insulative cellular non-aromaticpolymeric material includes the following: at least one primary resincomprising a high melt strength long chain branched polypropylene, atleast one secondary resin comprising a high crystalline polypropylenehomopolymer or an impact copolymer, at least one nucleating agent, atleast one blowing agent, and at least one slip agent. Optionally, acolorant may be incorporated.

The formulation may be introduced into an extruder via a hopper, such asthat shown in FIG. 1. During the extrusion process the formulation isheated and melted to form a molten resin mixture. In exemplaryembodiments, at least one physical blowing agent is introduced into themolten resin mixture via one or more ports in the extruder. The moltenresin mixture and gas is then extruded through a die.

In another exemplary embodiment, the formulation may contain both atleast one chemical blowing agent and at least one physical blowingagent.

Cups or other containers or structures may be formed from the sheetaccording to conventional apparatus and methods.

For the purposes of non-limiting illustration only, formation of a cupfrom an exemplary embodiment of a material disclosed herein will bedescribed; however, the container may be in any of a variety of possibleshapes or structures or for a variety of applications, such as, but notlimited to, a conventional beverage cup, storage container, bottle, orthe like. For the purpose of nonlimiting illustration only, a liquidbeverage will be used as the material which can be contained by thecontainer; however, the container may hold liquids, solids, gels,combinations thereof, or other material.

A material-forming process 100 is shown, for example, in FIG. 1.Material-forming process 100 extrudes a non-aromatic polymeric materialinto a sheet or strip of insulative cellular non-aromatic polymericmaterial 82 as suggested in FIG. 1. As an example, material-formingprocess 100 uses a tandem-extrusion technique in which a first extruder111 and a second extruder 112 cooperate to extrude strip of insulativecellular non-aromatic polymeric material 82.

As shown in FIG. 1, a formulation 121 of insulative cellularnon-aromatic polymeric material 82 is loaded into a hopper 113 coupledto first extruder 111. The formulation 121 may be in pellet, granularflake, powder, or other suitable form. Formulation 121 of insulativecellular non-aromatic polymeric material is moved from hopper 113 by ascrew 114 included in first extruder 111. Formulation 121 is transformedinto a molten resin 122 in a first extrusion zone of first extruder 111by application of heat 105 and pressure from screw 114 as suggested inFIG. 1. In exemplary embodiments a physical blowing agent 115 may beintroduced and mixed into molten resin 122 after molten resin 122 isestablished. In exemplary embodiments, as discussed further herein, thephysical blowing agent may be a gas introduced as a pressurized liquidvia a port 115A and mixed with molten resin 122 to form a moltenextrusion resin mixture 123, as shown in FIG. 1.

Extrusion resin mixture 123 is conveyed by screw 114 into a secondextrusion zone included in second extruder 112 as shown in FIG. 1.There, extrusion resin mixture 123 is further processed by secondextruder 112 before being expelled through an extrusion die 116 coupledto an end of second extruder 112 to form an extrudate 124. As extrusionresin mixture 123 passes through extrusion die 116, gas 115 comes out ofsolution in extrusion resin mixture 123 and begins to form cells andexpand so that extrudate 124 is established. As an exemplary embodimentshown in FIG. 1 the extrudate 124 may be formed by an annular extrusiondie 116 to form a tubular extrudate. A slitter 117 then cuts extrudate124 to establish a sheet or strip 82 of insulative cellular non-aromaticpolymeric material as shown in FIG. 1.

Extrudate means the material that exits an extrusion die. The extrudatematerial may be in a form such as, but not limited to, a sheet, strip,tube, thread, pellet, granule or other structure that is the result ofextrusion of a polymer-based formulation as described herein through anextruder die. For the purposes of illustration only, a sheet will bereferred to as a representative extrudate structure that may be formed,but is intended to include the structures discussed herein. Theextrudate may be further formed into any of a variety of final products,such as, but not limited to, cups, containers, trays, wraps, wound rollsof strips of insulative cellular non-aromatic polymeric material, or thelike.

As an example, strip 82 of insulative cellular non-aromatic polymericmaterial is wound to form a roll of insulative cellular non-aromaticpolymeric material and stored for later use. However, it is within thescope of the present disclosure for strip 82 of insulative cellularnon-aromatic polymeric material to be used in-line with the cup-formingprocess. In one illustrative example, strip 82 of insulative cellularnon-aromatic polymeric material is laminated with a skin having a filmand an ink layer printed on the film to provide high-quality graphics.

An insulative cup 10 is formed using a strip 82 of insulative cellularnon-aromatic polymeric material as shown in FIGS. 2 and 3. Insulativecup 10 includes, for example, a body 11 having a sleeve-shaped side wall18 and a floor 20 coupled to body 11 to cooperate with the side wall 18to form an interior region 14 for storing food, liquid, or any suitableproduct as shown in FIG. 2. Body 11 also includes a rolled brim 16coupled to an upper end of side wall 18 and a floor mount 17 coupled toa lower end of side wall 18 and to the floor 20 as illustrated in FIGS.2 and 7.

Body 11 is formed from a strip 82 of insulative cellular non-aromaticpolymeric material as disclosed herein. In accordance with the presentdisclosure, strip 82 of insulative cellular non-aromatic polymericmaterial is configured through application of pressure and heat (thoughin exemplary embodiments configuration may be without application ofheat) to provide means for enabling localized plastic deformation in atleast one selected region of body 11 to provide a plastically deformedfirst sheet segment having a first density located in a first portion ofthe selected region of body 11 and a second sheet segment having asecond density lower than the first density located in an adjacentsecond portion of the selected region of body 11 without fracturing thesheet of insulative cellular non-aromatic polymeric material so that apredetermined insulative characteristic is maintained in body 11.

A first 101 of the selected regions of body 11 in which localizedplastic deformation is enabled by the insulative cellular non-aromaticpolymeric material is in sleeve-shaped side wall 18 as suggested inFIGS. 2, 5, and 6. Sleeve-shaped side wall 18 includes an upright innertab 514, an upright outer tab 512, and an upright fence 513 as suggestedin FIGS. 2, 5, and 6. Upright inner tab 514 is arranged to extendupwardly from floor 20 and configured to provide the first sheet segmenthaving the first density in the first 101 of the selected regions ofbody 11. Upright outer tab 512 is arranged to extend upwardly from floor20 and to mate with upright inner tab 514 along an interface Itherebetween as suggested in FIG. 6. Upright fence 513 is arranged tointerconnect upright inner and outer tabs 514, 512 and surround interiorregion 14. Upright fence 513 is configured to provide the second sheetsegment having the second density in the first 101 of the selectedregions of body 11 and cooperate with upright inner and outer tabs 514,512 to form sleeve-shaped side wall 18 as suggested in FIGS. 2-5.

A second 102 of the selected regions of body 11 in which localizedplastic deformation is enabled by the sheet of insulative cellularnon-aromatic polymeric material is in rolled brim 16 included in body 11as suggested in FIGS. 2, 4, 5, and 7. Rolled brim 16 is coupled to anupper end of sleeve-shaped side wall 18 to lie in spaced-apart relationto floor 20 and to frame an opening into interior region 14. Rolled brim16 includes an inner rolled tab 164, an outer rolled tab 162, and arolled lip 163 as suggested in FIGS. 2, 4, 5, and 7. Inner rolled tab164 is configured to provide the first sheet segment in the second 102of the selected regions of body 11. Inner rolled tab 164 is coupled toan upper end of upright outer tab 512 included in sleeve-shaped sidewall 18. Outer rolled tab 162 is coupled to an upper end of uprightinner tab 514 included in sleeve-shaped side wall 18 and to an outwardlyfacing exterior surface of inner rolled tab 164. Rolled lip 163 isarranged to interconnect oppositely facing side edges of each of innerand outer rolled tabs 164, 162. Rolled lip 163 is configured to providethe second sheet segment having the second density in the second 102 ofthe selected region of body 11 and cooperate with inner and outer rolledtabs 164, 162 to form rolled brim 16 as suggested in FIG. 2.

A third 103 of the selected regions of body 11 in which localizedplastic deformation is enabled by the sheet of insulative cellularnon-aromatic polymeric material is in a floor mount included in body 11as suggested in FIGS. 2, 5, and 8. Floor mount 17 is coupled to a lowerend of sleeve-shaped side wall 18 to lie in spaced-apart relation torolled brim 16 and to floor 20 to support floor 20 in a stationaryposition relative to sleeve-shaped side wall 18 to form interior region14. Floor mount 17 includes a web-support ring 126, a floor-retainingflange 26, and a web 25. Web-support ring 126 is coupled to the lowerend of sleeve-shaped side wall 18 and configured to provide the secondsheet segment having the second density in the third 103 of the selectedregions of body 11. Floor-retaining flange 26 is coupled to floor 20 andarranged to be surrounded by web-support ring 126. Web 25 is arranged tointerconnect floor-retaining flange 26 and web-support ring 126. Web 25is configured to provide the first sheet segment having the firstdensity in the third 103 of the selected regions of body 11.

A fourth 104 of the selected regions of body 11 in which localizedplastic deformation is enabled by the sheet of insulative cellularnon-aromatic polymeric material is in floor-retaining flange of floormount 17 as suggested in FIGS. 2, 5, and 9. Floor-retaining flange 26includes an alternating series of upright thick and thin staves arrangedin side-to-side relation to extend upwardly from web 25 toward interiorregion 14 bounded by sleeve-shaped side wall 18 and floor 20. A first261 of the upright thick staves is configured to include a right sideedge extending upwardly from web 25 toward interior region 14. A second262 of the upright thick staves is configured to include a left sideedge arranged to extend upwardly from web 25 toward interior region 14and lie in spaced-apart confronting relation to right side edge of thefirst 261 of the upright thick staves. A first 260 of the upright thinstaves is arranged to interconnect left side edge of the first 261 ofthe upright thick staves and right side edge of the second 262 of theupright thick staves and to cooperate with left and right side edges todefine therebetween a vertical channel 263 opening inwardly into a lowerinterior region bounded by floor-retaining flange 26 and a horizontalplatform 21 included in floor 20 and located above floor-retainingflange 26. The first 260 of the upright thin staves is configured toprovide the first sheet segment in the fourth 104 of the selectedregions of body 11. The first 261 of the upright thick staves isconfigured to provide the second sheet segment in the fourth 104 of theselected regions of the body 11.

The compressibility of the insulative cellular non-aromatic polymericmaterial used to produce insulative cup 10 allows the insulativecellular non-aromatic polymeric material to be prepared for themechanical assembly of insulative cup 10, without limitationsexperienced by other non-aromatic polymeric materials. The cellularnature of the material provides insulative characteristics as discussedbelow, while susceptibility to plastic deformation permits yielding ofthe material without fracture. The plastic deformation experienced whenthe insulative cellular non-aromatic polymeric material is subjected toa pressure load is used to form a permanent set in the insulativecellular non-aromatic polymeric material after the pressure load hasbeen removed. In some locations, the locations of permanent set arepositioned to provide controlled gathering of the sheet of insulativecellular non-aromatic polymeric material.

The plastic deformation may also be used to create fold lines in thesheet to control deformation of the sheet when being worked during theassembly process. When deformation is present, the absence of materialin the voids formed by the deformation provides relief to allow thematerial to be easily folded at the locations of deformation.

A potential unexpected feature of the sheet of insulative cellularnon-aromatic polymeric material formed as described herein is the highinsulation value obtained at a given thickness. See, for example,Examples 1 and 2 below.

A potential feature of a cup formed of insulative cellular non-aromaticpolymeric material according to exemplary embodiments of the presentdisclosure is that the cup has low material loss. Furthermore, thematerial of the present disclosure may have markedly low off-gassingwhen subjected to heat from a conventional kitchen-type microwave ovenfor periods of time up to several minutes.

Another potential feature of a cup formed of the insulative cellularnon-aromatic polymeric material according to the present disclosure isthat the cup can be placed in and go through a conventional residentialor commercial dishwasher cleaning cycle (top rack) without noticeablestructural or material breakdown or adverse affect on materialproperties. This is in comparison to beaded expanded polystyrene cups orcontainers which can break down under similar cleaning processes.Accordingly, a cup made according to one aspect of the presentdisclosure can be cleaned and reused.

Another potential feature of an article formed of the insulativecellular non-aromatic polymeric material according to various aspects ofthe present disclosure is that the article can be recycled. Recyclablemeans that a material can be added (such as regrind) back into anextrusion or other formation process without segregation of componentsof the material, i.e., an article formed of the material does not haveto be manipulated to remove one or more materials or components prior tore-entering the extrusion process. For example, a cup having a printedfilm layer laminated to the exterior of the cup may be recyclable if onedoes not need to separate out the film layer prior to the cup beingground into particles. In contrast, a paper-wrapped expanded polystyrenecup may not be recyclable because the polystyrene material could notpracticably be used as material in forming an expanded polystyrene cup,even though the cup material may possibly be formed into anotherproduct. As a further example, a cup formed from a non-expandedpolystyrene material having a layer of non-styrene printed film adheredthereto may be considered non-recyclable because it would require thesegregation of the polystyrene cup material from the non-styrene filmlayer, which would not be desirable to introduce as part of the regrindinto the extrusion process.

Recyclability of articles formed from the insulative cellularnon-aromatic polymeric material of the present disclosure minimizes theamount of disposable waste created. In comparison, beaded expandedpolystyrene cups break up into beads and thus ordinarily cannot easilybe reused in a manufacturing process with the same material from whichthe article was formed. And, paper cups that typically have an extrusioncoated plastic layer or a plastic lamination for liquid resistanceordinarily cannot be recycled because the different materials (paper,adhesive, film, plastic) normally cannot be practicably separated incommercial recycling operations.

A potential feature of a cup or other article formed of materialaccording to one aspect (a non-laminate process) of the presentdisclosure is that the outside (or inside or both) wall surface of theinsulative cellular non-aromatic polypropylene sheet (prior to beingformed into a cup, or during cup formation, depending on themanufacturing process employed) can accept printing of high-resolutiongraphics. Conventional beaded expanded polystyrene cups have a surfacewhich typically is not smooth enough to accept printing other thanlow-resolution graphics. Similarly, known uncoated paper cups alsotypically do not have a smooth enough surface for such high-resolutiongraphics. Paper cups can be coated to have the desired surface finishand can achieve high resolution. Paper has difficulty reachinginsulation levels and requires a designed air gap incorporated into orassociated with the cup to achieve insulation, such as a sleeve slidonto and over a portion of the cup. Accordingly, solutions have been touse low-resolution printing, laminate to the outside wall a film whichhas been printed, or to have a printed sleeve (either bonded orremovable) inserted over the outside wall or coat the paper to accepthigh resolution graphics.

A potential feature of a cup formed of the insulative cellularnon-aromatic polymeric material according to one aspect of the presentdisclosure is that it possesses unexpected strength as measured byrigidity. Rigidity is a measurement done at room temperature and at anelevated temperature (e.g., by filling the cup with a hot liquid) andmeasuring the rigidity of the material. The strength of the cup materialis important to reduce the potential for the cup being deformed by auser and the lid popping off or the lid or sidewall seal leaking.

A potential feature of a cup formed of the insulative cellularnon-aromatic polymeric material according to the present disclosure isthat the sleeve is resistant to puncture, such as by a straw, fork,spoon, finger nail, or the like, as measured by standard impact testing,as described hereinbelow. Test materials demonstrated substantiallyhigher impact resistance when compared to a beaded expanded polystyrenecup. Accordingly, a cup formed as described herein can reduce thelikelihood of puncture and leakage of hot liquid onto a user.

A feature of a cup with a compressed brim and seam formed of thematerial according to one aspect as described herein is that a greaternumber of such cups can be nested in a given sleeve length because theseam is thinner and the side wall angle can be minimized (i.e., moreapproaching 90° with respect to the cup bottom) while providing asufficient air gap to permit easy de-nesting. Conventionally seam-formedcups having a seam substantially thicker than the side wall requires agreater side wall angle (and air gap) to allow for de-nesting, resultingin fewer cups being able to be nested in a given sleeve length.

A feature of a cup formed of the material according to one aspect of thepresent disclosure is that the brim may have a cross-section profile ofless than about 0.170 inches (4.318 mm) which may be due to localizedcell deformation and compression. Such a small profile is moreaesthetically pleasing than a larger profile.

A feature of a cup formed of the material according to one aspect of thepresent disclosure is that the rolled brim diameter can be the same forcups of different volumes, enabling one lid size to be used fordifferent cup sizes, assuming the cup rims outside diameters are thesame. As a result, the number of different size lids in inventory and atthe point of use may be reduced.

The material formulation may have properties that allow the sheet to becompressed without fracturing.

The insulative cellular non-aromatic polymeric material of the presentdisclosure may be formed into a strip which can be wrapped around otherstructures. For example, a strip of the material according to one aspectof the present disclosure that can be used as a wrapping material may beformed and wrapped around a pipe, conduit, or other structure to provideimproved insulation. The sheet or strip may have a layer of adhesive,such as a pressure sensitive adhesive, applied to one or both faces. Thestrip may be wound onto a roll. Optionally, the strip may have a releaseliner associated therewith to make unwinding the strip from the rolleasier. The polymer formulation may be adapted to provide the requisiteflexibility to form a wrap or windable strip, for example, by using oneor more polypropylene or other polyolefin materials that have sufficientflexibility to enable the extruded sheet to be flexible enough to bewound onto a roll. The insulative cellular non-aromatic polymericmaterial may be formed into a sleeve that can be inserted over a cup toprovide additional insulation.

In exemplary embodiments sheets formed from the insulative cellularnon-aromatic polymeric material of the present disclosure may be cut atthe die or be flaked and used as a bulk insulator.

The formulation and insulative cellular non-aromatic polymeric materialof the present disclosure satisfies a long-felt need for a material thatcan be formed into an article, such as a cup, that includes many if notall of the features of insulative performance, ready for recyclability,puncture resistance, frangibility resistance, microwavability and otherfeatures as discussed herein. Others have failed to provide a materialthat achieves combinations of these features as reflected in theappended claims. This failure is a result of the features beingassociated with competitive design choices. As an example, others havecreated materials and structures therefrom that based on design choicesare insulated but suffer from poor puncture resistance, inability toeffectively be recyclable, and lack microwavability. In comparison, theformulations and materials disclosed herein overcome the failures ofothers by using an insulative cellular non-aromatic polymeric material.Reference is hereby made to U.S. application Ser. No. 13/491,007 filedJun. 7, 2012 and entitled INSULATED CONTAINER for disclosure relating toarticles, such as cups, formed from such insulative cellularnon-aromatic polymeric materials, which application is herebyincorporated in its entirety herein.

EXAMPLES

The following examples are set forth for purposes of illustration only.Parts and percentages appearing in such examples are by weight unlessotherwise stipulated. All ASTM, ISO and other standard test method citedor referred to in this disclosure are incorporated by reference in theirentirety.

Example 1 Formulation and Extrusion

DAPLOY™ WB 140 polypropylene homopolymer (available from Borealis A/S)was used as the polypropylene base resin. F020HC, available fromBraskem, a polypropylene homopolymer resin, was used as the secondaryresin. The two resins were blended with: Hydrocerol™ CF-40E™ as aprimary nucleation agent, talc as a secondary nucleation agent, CO₂ as ablowing agent, a slip agent, and titanium dioxide as a colorant.Percentages were:

79.9%   Primary resin: high melt strength polypropylene Borealis WB140HMS15% Secondary resin: F020HC (Braskem) 0.1%   Primary nucleatingagent: Clariant Hyrocerol CF-40E ™ 2% Secondary nucleating agent: Talc1% Colorant: TiO₂ PE (alternatively, PP can be used) 2% Slip agent:Ampacet ™ 102823 LLDPE (linear low-density polyethylene), available fromAmpacet Corporation

The formulation was added to an extruder hopper. The extruder heated theformulation to form a molten resin mixture. To this mixture was added

1.1 lbs/hr CO₂

0.7 lbs/hr R134a

The carbon dioxide with R134a was injected into the resin blend toexpand the resin and reduce density. The mixture thus formed wasextruded through a die head into a sheet. The sheet was then cut andformed into a cup.

Example 1 Test Results

The test results of the material formed according to Example 1 showedthe material had a density of about 0.1902 g/cm³ and a nominal sheetgauge of about 0.089 inches (2.2606 mm).

Microwavability

Containers produced using this material filled with 12 ounces of roomtemperature water were heated in a FISO Microwave Station (1200 Watts)microwave oven for 2.5 min without burning or scorching or other visibleeffect on the cup. In comparison, paper cups heated in the samemicrowave oven scorched or burned in less than 90 seconds.

Rigidity

Test Method

Samples were at 73° F. (22.8° C.) and 50% relative humidity. The CupStiffness/Rigidity test was conducted with a horizontal force gaugecontaining a load cell to measure the resisting force of the cup whenexposed to the following test conditions: (a) The test location on thecup was ⅓ down from the rim of the cup; (b) testing travel distance is0.25 inches (6.35 mm); and (c) testing travel time was 10 seconds.

Test Results

With an average wall thickness of about 0.064 inches (1.6256 mm),average density of about 0.1776 g/cm³, and average cup weight of about9.86 g, the rigidity of the material are shown below in Tables 1-2.

TABLE 1 Rigidity Test Results Rigidities (kg-F) Cup # Seam 90° from SeamAverage unlidded/unfilled 1 0.64 0.654 0.647 2 0.646 0.672 0.659 3 0.6320.642 0.637 4 0.562 0.608 0.585 5 0.652 0.596 0.624 0.630 STD DEV 0.0283sigma 0.085 High Range 0.716 Low Range 0.545 lidded/unfilled 6 0.890.83 0.860 7 0.954 0.904 0.929 8 0.846 0.808 0.827 9 0.732 0.826 0.77910 0.87 0.792 0.831 0.845 STD DEV 0.055 3sigma 0.165 High Range 1.011Low Range 0.680 unlidded/filled 200° F. 11 0.274 0.290 0.282 12 0.2780.326 0.302 13 0.264 0.274 0.269 14 0.300 0.270 0.285 15 0.252 0.2800.266 0.281 STD DEV 0.014 3sigma 0.043 High Range 0.324 Low Range 0.238lidded/filled 200° F. 16 0.346 0.354 0.350 17 0.386 0.422 0.404 18 0.3580.364 0.361 19 0.338 0.374 0.356 20 0.304 0.272 0.288 0.352 STD DEV0.042 3sigma 0.125 High Range 0.476 Low Range 0.227 unlidded/filled icewater 21 0.796 0.730 0.763 22 0.818 0.826 0.822 23 0.894 0.760 0.827 240.776 0.844 0.810 25 0.804 0.714 0.759 0.796 STD DEV 0.033 3sigma 0.098High Range 0.894 Low Range 0.698 lidded/filled ice water 26 1.044 0.8920.968 27 1.146 1.018 1.082 28 0.988 1.054 1.021 29 1.012 1.106 1.059 300.826 1.058 0.942 1.014 STD DEV 0.059 3sigma 0.177 High Range 1.192 LowRange 0.837

TABLE 2 Summary of Rigidity Test Results Unfilled Kg-F Wall(kilograms-force) Hot Fill 200° F. Kg-F Ice Water Fill 35° F. Kg-FThickness Density Unlidded Lidded Unlidded Lidded Unlidded Lidded Inchesg/cc Test material 0.630 0.845 0.281 0.352 0.796 1.014 0.064 0.1776Insulation

Test Method

A typical industrial cup insulation test method as follows was used:

-   -   Attach the (cup exterior) surface temperature thermocouple to        cup with glue.    -   Tape attached thermocouple to cup with cellophane tape so that        the thermocouple is in the middle of the cup opposite the seam.    -   Heat water or other aqueous liquid to near boiling, such as in a        microwave.    -   Continually stir the hot liquid with a bulb thermometer while        observing the liquid temperature.    -   Record thermocouple temperature.    -   When the liquid gets to 200° F. pour into cup to near full.    -   Place lid on cup.    -   Record surface temperature for a minimum of 5 minutes.

Material thickness was about 0.089 inches (2.2606 mm). The density wasabout 0.1902 g/cm³.

Test Results

A cup formed from the formulation noted above was used having a densityof about 0.190 g/cm³ and a wall thickness of about 0.089 inches. A hotliquid at 200° F. (93.3° C.) was placed in the cup.

Test Results

The temperature measured on the outside wall of the cup was about 140.5°F. (60.3° C.) resulting in drop of about 59.5° F. (33° C.). The maximumtemperature over a five-minute period was observed to peak at about140.5° F. (60.3° C.). The lower the temperature, the better theinsulation property of the cup material as the material reduces the heattransferring from the liquid to the cup material exterior.

Frangibility

Frangibility can be defined as resistance to tear or punctures causingfragmentation.

Test Method

The Elmendorf test method described in ASTM D1922-93 was used. Theradius of tear was 1.7 inches (43.18 mm).

Test Results

The test results are shown in Tables 3-4 below. The material as formedin one exemplary embodiment of the present disclosure provides superiorresistance to tear forces when compared to EPS.

TABLE 3 Test Results Machine Direction (gram force) Transverse Direction(gram force) Test Test Test Test Test std Test Test Test Test Test stdTag 1 2 3 4 5 mean dev. 1 2 3 4 5 mean dev. Test 288 262 288 258 315 28223 232 213 178 205 232 212 23 Material EPS 108 114 112 116 110 112 3 *

TABLE 4 Summary of Test Results Test material cup Tear Strength SampleID → (mean) Elmendorf Tear machine direction (MD) g (gram) 800 ArmElmendorf Tear MD gf (gram force) 282 Elmendorf Tear transversedirection g 800 (TD) Arm Elmendorf Tear TD gf 212 Expanded polystyreneTear Strength (mean) Elmendorf Tear Arm 800 Elmendorf Tear 112

Note that there was no data obtained for the transverse direction testfor expanded polystyrene because expanded polystyrene does not have amaterial orientation, i.e., a machine or transverse direction, due tothe manufacturing process. The range (calculated as: lowerrange=mean−(3× std dev); upper range=mean+(3× std dev)) for the testedmaterial of the present disclosure was about 213 grams-force to about351 grams-force in the machine direction and about 143 grams-force toabout 281 grams-force in the transverse direction. In comparison, therange of the expanded polystyrene material tested was about 103grams-force to about 121 grams-force.

Puncture Resistance

Test Method

Determine the force and travel needed to puncture cup sidewall andbottom. An Instron instrument is used in compression mode set to 10inches (254 mm) per minute travel speed. The cup puncture test fixtureon base of Instron is used. This fixture allows the cup to fit over ashape that fits inside the cup with a top surface that is perpendicularto the travel of the Instron tester. The one inch diameter hole of thefixture should be positioned up. The portion of the Instron that movesshould be fitted with a 0.300 inch (7.62 mm) diameter punch. The punchwith the hole is aligned in the test fixture. The cup is placed over thefixture and the force and travel needed to puncture the cup sidewall isrecorded. The sidewall puncture test is repeated in three evenly spacedlocations while not puncture testing on the seam of the cup. The bottomof the cup is tested. This should be done in the same manner as thesidewall test except no fixture is used. The cup is just placed upsidedown on the base of the Instron while bringing the punch down on thecenter of the cup bottom.

Test Results

Results of the typical sidewall puncture and the bottom puncture areshown in Table 5 below.

TABLE 5 Puncture Test Results Cavity # Max Load (lbf) Ext. @ Max Load(in) Expanded polystyrene 3.79 0.300 tested insulative cellular 22.180.292 non-aromatic polymeric material (No Rim)Slow Puncture Resistance—Straw

Test Method

The material as formed in one exemplary embodiment of the presentdisclosure provides superior resistance to punctures when compared toexpanded polystyrene using the Slow Puncture Resistance Test Method asdescribed in ASTM D-3763-86. The test results are shown in Tables 6-9below.

Test Results

TABLE 6 Tested Material Elongation At Specimen # Peak Load g(f) Break(mm) 1 13876.49 — 2 13684.33 — 3 15121.53 — 4 15268.95 17 5 14970.47 206 13049.71 — 7 15648.44 17 8 15352.38 23 9 18271.37 — 10  16859.29 —Mean 15210.30 19 Std. Dev. 1532.83  3

TABLE 7 Comparison: Expanded Polystyrene Elongation At Specimen # PeakLoad g(f) Break (mm) 1 2936.73 — 2 2870.07 10 3 2572.62 — 4 2632.44 — 52809.70 — 6 2842.93 — 7 2654.55 — 8 2872.96 — 9 2487.63 — 10  2866.53 —11  2803.25 — 12  2775.22 — 13  2834.28 — 14  2569.97 — Mean 2752.06 10Std. Dev. 140.42 —

TABLE 8 Paper Wrapped Expanded Polystyrene Elongation At Specimen # PeakLoad g(f) Break (mm) 1 7930.61 — 2 10044.30 — 3 9849.01 — 4 8711.44 — 59596.79 — 6 9302.99 — 7 10252.27 — 8 7785.64 — 9 8437.28 — 10  6751.98 —11  9993.19 — Mean 8968.68 — Std. Dev. 1134.68 —

TABLE 9 Summary of Slow Puncture-Straw Test Results Sample ID Testedinsulative cellular non- Paper wrapped expanded aromatic polymericmaterial cup Expanded polystyrene polystyrene (mean) grams-force (mean)grams-force (gf) (mean) grams-force (gf) (gf) Average gf: 15210 27528969

Example 2 Formulation and Extrusion

The following formulation was used:

-   -   81.70% Borealis WB 140HMS primary polypropylene    -   0.25% Amco A18035 PPRO talc filled concentrate    -   2% Ampacet 102823 Process Aid PE MB linear low density        polyethylene slip agent    -   0.05% Hydrocerol CF-40E chemical foaming agent    -   1% Colortech 11933-19 colorant    -   15% Braskem F020HC high crystallinity homopolymer polypropylene    -   3.4 lbs/hour of CO₂ was introduced into the molten resin.

Density of the strip formed ranged from about 0.155 g/cm³ to about 0.182g/cm³.

The formulation was added to an extruder hopper. The extruder heated theformulation to form a molten resin mixture. To this mixture was addedthe CO₂ to expand the resin and reduce density. The mixture thus formedwas extruded through a die head into a strip 82. The strip was then cutand formed into insulative cup 10.

Example 2 Test Results

In exemplary embodiments, a tube of extruded insulative cellularnon-aromatic polymeric material has two surfaces that are formed underdifferent cooling conditions when the material is extruded. One surface,which will be further referenced as the outside surface of extrudedtube, is in contact with air, and does not have physical barriersrestricting the expansion. The outside surface of extruded tube surfaceis cooled by blowing compressed air at cooling rate equal or higher than12° F. per second. Surface on the opposite side will be referenced asinside of extruded tube. The inside of extruded tube surface is formedwhen the extruded tube is drawn in the web or machine direction on themetal cooling surface of the torpedo mandrel that is physicallyrestricting the inside of extruded tube and is cooled by combination ofwater and compressed air at a cooling rate below 10° F. per second. Inexemplary embodiments, the cooling water temperature is about 135° F.(57.22° C.). In exemplary embodiments, the cooling air temperature isabout 85° F. (29.44° C.). As a result of different cooling mechanismsthe outside surface of extruded tube and inside of extruded tubesurfaces have different surface characteristics. It is known that thecooling rate and method affects the crystallization process ofpolypropylene altering its morphology (size of crystal domains) andtopography (surface profile and smoothness).

An unexpected feature of exemplary embodiments of an extruded sheet asdescribed herein is in the ability of the sheet to form a noticeablysmooth, crease and wrinkle free surface, when curved to form a roundarticle, such as cup. The surface is smooth and wrinkle free even insidethe cup, where compression forces typically cause material to crushcrease easily, especially for low density material with large cell size.In exemplary embodiments, the smoothness of the surface of an extrudedsheet of insulative cellular non-aromatic polymeric material as detectedby microscopy is such that the depth of the indentations (creases orwrinkles) naturally occurring in the outside and inside of the cupsurface when it is subject to extension and compression forces duringcup formation may be less than about 100 microns. In one exemplaryembodiment, the smoothness may be less than about 50 microns. In oneexemplary embodiment, the smoothness may be about 5 microns or less. Atabout 10 microns depth and less, the micro-wrinkles on cup surface areordinarily not visible to the naked eye.

In one exemplary embodiment, an insulative cup formed from a sheetcomprising a skin and a strip of insulative cellular non-aromaticpolymeric material had typical creases (deep wrinkle) about 200 micronsdeep extending from the top to bottom of the cup. In one exemplaryembodiment, an insulative cup formed from a sheet comprising a strip ofinsulative cellular non-aromatic polymeric material only (without askin) had typical creases about 200 microns deep extending from top tobottom of the cup. Such creases with depths from about 100 microns toabout 500 microns are typically formed when inside of extruded tube isfacing inside of the cup in a compression mode. Creases and deepwrinkles may present a problem of unsatisfactory surface quality makingfinal cups unusable or undesirable. Creases may form in instances wheresheets include a skin or exclude a skin.

In exemplary embodiments, the insulative cellular non-aromatic polymericmaterial may be extruded as strip. However microscopy images show thattwo distinct layers exist within the extruded strip, namely, dulloutside extruded tube layer and shiny inside extruded tube layer. Thedifference between the two layers is in reflectance of the surface dueto the difference in crystal domain size. If a black marker is used tocolor the surface examined by microscope, reflectance is eliminated andthe difference between the two surfaces may be minimal or undetectable.

In one exemplary embodiment, a sample strip was prepared without anyskin. Black marker was used to eliminate any difference in reflectancebetween the layers. Images showed that the cell size and celldistribution was the same throughout the strip thickness. A crease ofabout 200 microns deep was seen as a fold in the surface where the cellwall collapsed under the compression forces.

Differential scanning calorimetry analysis conducted on a TA InstrumentsDSC 2910 in nitrogen atmosphere showed that with an increase in coolingrate, the crystallization temperature and crystallinity degree decreasedfor the polymer matrix material of the strip, as shown below in Table10.

TABLE 10 Crystallization of polymer matrix Crystallization temp, in ° C.Crystallinity degree, in % Slow cooling Fast cooling Slow cooling Fastcooling 5° C./min 10° C./min 15° C./min 5° C./min 10° C./min 15° C./min135.3 131.5 129.0 49.2 48.2 47.4 Melting (2^(nd) heat) of polymer matrix(heating rate 10° C./min) after crystallization Melting temp, ° C.Crystallinity degree, % Slow cooling Fast cooling Slow cooling Fastcooling 5° C./min 10° C./min 15° C./min 5° C./min 10° C./min 15° C./min162.3 162.1 161.8 48.7 47.2 46.9

Differential scanning calorimetry data demonstrates the dependence ofcrystallization and subsequent 2^(nd) heat melting temperature andpercent crystallinity on the rate of cooling during crystallization.Exemplary embodiments of a strip of insulative cellular non-aromaticpolymeric material may have the melting temperature between about 160°C. (320° F.) and about 172° C. (341.6° F.), crystallization temperaturebetween about 108° C. (226.4° F.) and about 135° C. (275° F.), andpercent crystallinity between about 42% and about 62%.

In exemplary embodiments the extruded sheet as determined bydifferential scanning calorimetry at 10° C. per minute heating andcooling rate had a melting temperature of about 162° C. (323.6° F.),crystallization temperature of about 131° C. (267.8° F.) andcrystallinity degree of about 46%.

It was found unexpectedly that the outside extrusion tube surface worksfavorably in a compression mode without causing appreciable creasing andtherefore a cup (or other structure) may advantageously be made with theoutside extrusion tube surface facing inside of the insulative cup. Thedifference in the resistance of the inside extrusion tube layer andoutside extrusion tube layer to compression force may be due todifference in the morphology of the layers because they werecrystallized at different cooling rates.

In exemplary embodiments of formation of an extruded sheet, the insideextrusion tube surface may be cooled by combination of water cooling andcompressed air. The outside extrusion tube surface may be cooled bycompressed air by using torpedo with circulating water and air outlet.Faster cooling rates may result in the formation of smaller sizecrystals. Typically, the higher cooling rate, the greater the relativeamount of smaller crystals that is formed. X-Ray diffraction analysis ofan exemplary extruded sheet of insulative cellular non-aromaticpolymeric material was conducted on Panalytical X'pert MPD Prodiffractometer using Cu radiation at 45 KV/40 mA. It was confirmed thatthe outside extrusion tube surface had a crystal domain size of about 99angstrom, while the inside extrustion tube surface had a crystal domainsize of about 114 angstrom. In exemplary embodiments, an extruded stripof insulative cellular non-aromatic polymeric material may have acrystal domain size below about 200 angstroms. In exemplary embodiments,an extruded strip of insulative cellular non-aromatic polymeric materialmay have a crystal domain size preferably below about 115 angstroms. Inexemplary embodiments, an extruded strip of insulative cellularnon-aromatic polymeric material may have a crystal domain size belowabout 100 angstroms.

Rigidity

Test Method

The test method is the same as described for rigidity testing in Example1.

Test Results

The rigidity test results are shown in Table 11 below.

TABLE 11 unlidded/filled lidded/filled 200° F. 200° F. Rigidities (kg-F)Rigidities (kg-F) 90° 90° Wall from Aver- from Aver- Gram Thick- Sample#Seam Seam age Seam Seam age Weights ness B1 0.354 0.380 0.367 0.4700.528 0.499 12.6 0.0744 B2 0.426 0.464 0.445 0.598 0.610 0.604 13.0 B30.526 0.494 0.510 0.628 0.618 0.623 12.4 B4 0.592 0.566 0.579 0.7400.746 0.743 13.2 12.80 0.475 0.617 Density 0.1817Insulation

Test Method—Wall Temperature

An insulative cup formed from the formulation noted above was usedhaving a density of about 0.18 g/cm³ and a wall thickness of about 0.074inches (1.8796 mm). A hot liquid at 200° F. (93.3° C.) was placed in thecup.

Test Results

The temperature measured on the outside wall of the cup was about 151°F. (66.1° C.) with a drop of about 49.0° F. (27.2° C.). The maximumtemperature over a five-minute period was observed to peak at about 151°F. (66.1° C.).

Insulation testing in the form of thermal conductivity was done.

Test Method—Thermal Conductivity

This test measures bulk thermal conductivity (W/m−K), measured atambient temperature and at 93° C. (199.4° F.). A ThermTest TPS 2500 SThermal Constants Analyzer instrument was used, employing the testmethod of ISO/DIS 22007-2.2 and using the Low Density/High Insulatingoption. The TPS sensor #5501 0.2521 inch radius (6.403 mm radius) withKapton® insulation was used for all measurements. A 20 second test wasdone, using 0.02 Watts power. Data using points 100-200 were reported.

Test Results

The test results are shown in Table 12 below.

TABLE 12 Mean Thermal Conductivity Results Mean Thermal ConductivityStandard Deviation Temp. (° C.) (W/m-K) (W/m-K) 21 0.05792 0.00005 930.06680 0.00025

Although only a number of exemplary embodiments have been described indetail above, those skilled in the art will readily appreciate that manymodifications are possible in the exemplary embodiments withoutmaterially departing from the novel teachings and advantages.Accordingly, all such modifications are intended to be included withinthe scope of this disclosure as defined in the following claims.

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Ranges may be expressed herein as from “about” oneparticular value, and/or to “about” another particular value. When sucha range is expressed, another embodiment includes from the oneparticular value and/or to the other particular value. Similarly, whenvalues are expressed as approximations, by use of the antecedent“about,” it will be understood that the particular value forms anotherembodiment. It will be further understood that the endpoints of each ofthe ranges are significant both in relation to the other endpoint, andindependently of the other endpoint.

“Optional” or “optionally” means that the subsequently described eventor circumstance may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances where itdoes not.

Throughout the description and claims of this specification, the word“comprise” and variations of the word, such as “comprising” and“comprises,” means “including but not limited to,” and is not intendedto exclude, for example, other additives, components, integers or steps.“Exemplary” means “an example of” and is not intended to convey anindication of a preferred or ideal embodiment. “Such as” is not used ina restrictive sense, but for explanatory purposes.

Disclosed are components that can be used to perform the disclosedmethods, equipment, and systems. These and other components aredisclosed herein, and it is understood that when combinations, subsets,interactions, groups, etc. of these components are disclosed whilespecific reference of each various individual and collectivecombinations and permutation of these may not be explicitly disclosed,each is specifically contemplated and described herein, for all methods,equipment and systems. This applies to all aspects of this applicationincluding, but not limited to, steps in disclosed methods. Thus, ifthere are a variety of additional steps that can be performed it isunderstood that each of these additional steps can be performed with anyspecific embodiment or combination of embodiments of the disclosedmethods.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thescope or spirit. Other embodiments will be apparent to those skilled inthe art from consideration of the specification and practice disclosedherein. It is intended that the specification and examples be consideredas exemplary only.

It should further be noted that any publications and brochures referredto herein are incorporated by reference in their entirety.

The invention claimed is:
 1. A container comprising: a sleeve-shapedsidewall having an outer tab overlapping an inner tab, the sidewallcomprising an insulative cellular non-aromatic polymeric material; and afloor joined to at least a portion of the sidewall, the sidewall and thefloor defining an interior region having an open end, and the sidewallhaving a length extending from the floor to the open end; the insulativecellular non-aromatic polymeric material including: a first polymermaterial comprising high melt strength polypropylene having long chainbranching, and a second polymer material comprising at least one ofpolypropylene and polyethylene, the insulative cellular non-aromaticpolymeric material having a thermal conductivity to density ratio ofabout 0.3, wherein thermal conductivity is expressed in W/m−K at about21° C. and density is expressed in g/cm³; and the sleeve-shaped sidewallof the container having a rigidity to density ratio of about 1.5 toabout 2.6 for a sidewall thickness of about 0.064 inches to about 0.0744inches when the container is filled with a liquid of about 93.3° C.,wherein density is expressed in g/cm³ and rigidity is expressed inkg-force as measured about one-third of the length of the sleeve-shapedsidewall from the open end over a travel distance of about 0.25 inchesover a travel time of about 10 seconds.
 2. The container of claim 1,wherein the insulative cellular non-aromatic polymeric material has adensity of about 0.15 g/cm³ to about 0.19 g/cm³.
 3. The container ofclaim 1, wherein the insulative cellular non-aromatic polymeric materialhas a density of about 0.155 g/cm³ to about 0.1902 g/cm³.
 4. Thecontainer of claim 1, wherein the inner tab of the sleeve-shapedsidewall has a first density, portions of the sleeve-shaped sidewallapart from the inner tab have a second density, and the second densityis lower than the first density.
 5. The container of claim 1, whereinthe second polymer material comprises at least one of a polypropylenecopolymer and a polypropylene homopolymer.
 6. The container of claim 1,wherein the insulative cellular non-aromatic polymeric material has adensity of about 0.155 g/cm³ to about 0.182 g/cm³ and wherein theinsulative cellular non-aromatic polymeric material is an extrudate, andcells of the extrudate have a first dimension along a first axis and asecond dimension along a second axis, the second axis is normal to thefirst axis, and wherein an average ratio of the first dimension to thesecond dimension is about 1.5 to about 3.0.
 7. The container of claim 6,wherein the cells of the extrudate have an average aspect ratio ofbetween about 1.0 and about 3.0 along the first axis.
 8. The containerof claim 7, wherein the sleeve-shaped sidewall defines a circumferenceof the open end and the circumference is aligned with the first axis. 9.The container of claim 6, wherein the cells of the extrudate have anaverage aspect ratio of between about 1.0 and about 2.0 along the secondaxis.
 10. The container of claim 9, wherein the sleeve-shaped sidewalldefines a circumference of the open end and the circumference is alignedwith the second axis.
 11. The container of claim 1, wherein theinsulative cellular non-aromatic polymeric material is an extrudate, andcells of the extrudate have a first dimension along a first axis and asecond dimension along a second axis, the second axis is normal to thefirst axis, and wherein an average ratio of the first dimension to thesecond dimension is about 1.5 to about 3.0.
 12. The container of claim11, wherein the cells of the extrudate have an average aspect ratio ofbetween about 1.0 and about 2.0 along the second axis.
 13. The containerof claim 12, wherein the sleeve-shaped sidewall defines a circumferenceof the open end and the circumference is aligned with the second axis.14. The container of claim 13, wherein the sleeve-shaped sidewall has afirst surface facing the interior region and a second surface oppositethe first surface and the first surface substantially lacks creases witha depth exceeding about 200 microns.
 15. The container of claim 1,wherein the sleeve-shaped sidewall has a first surface facing theinterior region and a second surface opposite the first surface, thefirst surface is characterized by a first polymer crystal domain size,the second surface is characterized by a second polymer crystal domainsize, and the first polymer crystal domain size is smaller than thesecond polymer crystal domain size.
 16. The container of claim 15,wherein the first polymer crystal domain size is less than about 200angstroms.
 17. The container of claim 16, wherein the container furtherincludes a rolled brim at the open end of the interior region.
 18. Thecontainer of claim 17, wherein the second density is about 0.05 g/cm³ toabout 0.19 g/cm³.
 19. An insulative cellular non-aromatic polymericextrudate comprising: a first polymer material comprising high meltstrength polypropylene having long chain branching, a second polymermaterial comprising at least one of polypropylene and polyethylene, andthe insulative cellular non-aromatic polymeric extrudate having athermal conductivity to density ratio of about 0.3, wherein thermalconductivity is expressed in W/m−K at about 21° C. and density isexpressed in g/cm³; and the insulative cellular non-aromatic polymericextrudate having a tear resistance of between about 2 grams-force/milthickness to about 3.5 grams-force/mil thickness according to ASTMD1922-93 with a tear radius of about 1.7 inches.
 20. The insulativecellular non-aromatic polymeric extrudate of claim 19, wherein theextrudate has a thickness of about 0.089 inches.
 21. The insulativecellular non-aromatic polymeric extrudate of claim 19, wherein theextrudate has a density of about 0.155 g/cm³ to about 0.1902 g/cm³. 22.The insulative cellular non-aromatic polymeric extrudate of claim 19,wherein cells of the extrudate have a first dimension along a first axisand a second dimension along a second axis, the second axis is normal tothe first axis, and wherein an average ratio of the first dimension tothe second dimension is about 1.5 to about 3.0.
 23. The insulativecellular non-aromatic polymeric extrudate of claim 19, wherein thesecond polymer material comprises at least one of a polypropylenecopolymer and a polypropylene homopolymer.
 24. The insulative cellularnon-aromatic polymeric extrudate of claim 19, wherein cells of theextrudate have a first dimension along a first axis and a seconddimension along a second axis, the second axis is normal to the firstaxis, and an average length of the first dimension is greater than anaverage length of the second dimension, and wherein the extrudate has atear resistance of between about 213 grams-force and about 351grams-force along the first axis for an extrudate thickness of about0.089 inches according to ASTM D1922-93 with a tear radius of about 1.7inches.
 25. The insulative cellular non-aromatic polymeric extrudate ofclaim 24, wherein the extrudate has a tear resistance of between about143 grams-force and about 281 grams-force along the second axis for anextrudate thickness of about 0.089 inches according to ASTM D1922-93with a tear radius of about 1.7 inches.
 26. The insulative cellularnon-aromatic polymeric extrudate of claim 19, wherein cells of theextrudate have a first dimension along a first axis and a seconddimension along a second axis, the second axis is normal to the firstaxis, and wherein an average ratio of the first dimension to the seconddimension is about 1.5 to about 3.0.
 27. The insulative cellularnon-aromatic polymeric extrudate of claim 26, wherein the cells of theextrudate have an average aspect ratio of between about 1.0 and about3.0 along the first axis.
 28. The insulative cellular non-aromaticpolymeric extrudate of claim 27, wherein cells of the extrudate have anaverage aspect ratio of between about 1.0 and about 2.0 along the secondaxis.
 29. The insulative cellular non-aromatic polymeric extrudate ofclaim 19, wherein the extrudate has a first surface and a second surfaceopposite the first surface, the first surface being characterized by afirst polymer crystal domain size, the second surface beingcharacterized by a second polymer crystal domain size, and the firstpolymer crystal domain size being smaller than the second polymercrystal domain size.
 30. The insulative cellular non-aromatic polymericextrudate of claim 29, wherein the first polymer crystal domain size isless than about 200 angstroms.